The present invention concerns a water fitting, particularly for domestic sanitary installations. The present invention particularly concerns such water fittings having a turbine wheel arranged in a flow duct and acted on by a flow of water to drive a sealed electrical generator.
Such a water fitting is, for example, known from the international Patent application published under the number WO 85/01337. This reveals a water dispenser whose water flow can be switched on and off by means of an electrically controlled valve. A turbine wheel acted on by the water is located in the flow duct of the water dispenser upstream relative to the valve and this turbine wheel drives a low power electrical generator. The generator is connected to a control arrangement controlling the valve, it being possible to charge the accumulator of this arrangement with the electricity supplied by the generator. The circular cross-section flow duct of the water dispenser has a 90 degree bend, the turbine wheel being upstream of this bend and the axis of rotation of the turbine wheel coinciding with the longitudinal axis of the tubular casing bounding the flow duct in this region. The generator is aligned with the turbine and is located outside the casing in the region of the 90 degrees bend, an opening being provided in the casing for the passage of the generator shaft coupled to the driven shaft of the turbine wheel.
A hat-shaped sealing element protruding through the opening in the casing into the flow duct is clamped between the generator and the casing of the water fitting. This sealing element has a hole extending in the axial direction for the driven shaft of the turbine wheel or the drive shaft of the generator. Between the inner surface of the sealing element and the generator shaft, there is an O-ring seal which, further in the axial direction, is in contact with the inner end surface of the sealing element and, opposite this, with a sealing disc provided on the generator shaft. This sealing arrangement leads to substantial losses relative to the low power of the turbine. In addition, it is subject to wear and aging which can lead to water penetrating into the inner part of the generator.
The object of the present invention is therefore to produce a water fitting having a turbine driven generator whose losses are extremely small and whose generator is reliably sealed against the flow duct independent of aging.